Hi Sans,
Not sure if you have fixed the issue with your modem as yet or still waiting on the tech to come out. I have had this same problem numerous times (with both Cox and Xfinity), have done the reboots, resets, tech out etc and have found the quickest way to resolve this issue is to take the moden and exchange it. Contrary to what your cable company would like you to believe or tell you, these are the best, most economical, modems the cable company can purchase or lease in bulk. In other words they are cheap. It is always easier and quicker to go exchange it after checking to make sure the connections are tight, it has rebooted, has the newest down loaded update etc rather than have a tech come out and check all the outlets, the pole box connection etc. You will know immediately after you get the new one home if you need a tech to come out (the new modem has the same issue). Hope that helps.
